1531729 has 2 divisors, whose sum is σ = 1531730. Its totient is φ = 1531728.

The previous prime is 1531721. The next prime is 1531769. The reversal of 1531729 is 9271351.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 859329 + 672400 = 927^2 + 820^2 .

It is a cyclic number.

It is not a de Polignac number, because 1531729 - 2³ = 1531721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1531697 and 1531706.

It is not a weakly prime, because it can be changed into another prime (1531721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 765864 + 765865.

It is an arithmetic number, because the mean of its divisors is an integer number (765865).

2^1531729 is an apocalyptic number.

It is an amenable number.

1531729 is a deficient number, since it is larger than the sum of its proper divisors (1).

1531729 is an equidigital number, since it uses as much as digits as its factorization.

1531729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1890, while the sum is 28.

The square root of 1531729 is about 1237.6303971703. The cubic root of 1531729 is about 115.2729245464.

It can be divided in two parts, 153172 and 9, that added together give a triangular number (153181 = T₅₅₃).

The spelling of 1531729 in words is "one million, five hundred thirty-one thousand, seven hundred twenty-nine".